Pilot Study of T-APCs Following CAR T Cell Immunotherapy for CD19+ Leukemia
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ClinicalTrials.gov Identifier: NCT03186118 |
Recruitment Status :
Active, not recruiting
First Posted : June 14, 2017
Last Update Posted : March 23, 2022
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Condition or disease | Intervention/treatment | Phase |
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CD 19+ Acute Leukemia | Biological: T-cell Antigen Presenting Cells expressing truncated CD19 (T-APC) | Phase 1 |
Study Type : | Interventional (Clinical Trial) |
Estimated Enrollment : | 30 participants |
Allocation: | Non-Randomized |
Intervention Model: | Parallel Assignment |
Intervention Model Description: | Subjects are assessed during the parent study for total CD 19 load in bone marrow. Participants meeting eligibility criteria are transitioned into one of 3 arms in PLAT-03. |
Masking: | None (Open Label) |
Primary Purpose: | Treatment |
Official Title: | Pediatric and Young Adult Leukemia Adoptive Therapy (PLAT)-03: A Pilot Feasibility and Safety Study of CD19t T-Antigen Presenting Cells (T-APCs) Following CAR T Cell Immunotherapy for CD19+ Leukemia |
Actual Study Start Date : | August 4, 2017 |
Actual Primary Completion Date : | September 13, 2021 |
Estimated Study Completion Date : | July 2033 |

Arm | Intervention/treatment |
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Experimental: Cohort A
Participants will receive CD19-targeting CAR T cells. Participants who have a total CD19 antigen load in bone marrow of <15% will be assigned to Cohort A, to receive up to 6 T-APC treatments.
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Biological: T-cell Antigen Presenting Cells expressing truncated CD19 (T-APC)
Autologous CD4 and CD8 T cells transduced to express a truncated CD19 (CD19t) Transgene
Other Name: CD19+ Chimeric Antigen Receptor T-cells (CAR-T cells) |
Experimental: Cohort B
Participants will receive CD19-targeting CAR T cells. Participants for whom laboratory testing on Study Day 14 indicates they are at risk for early loss of CAR T cells will be assigned to Cohort B to receive up to 6 T-APC treatments. If laboratory testing prior to planned T-APC treatment indicates loss of CAR-T cells, participants may move to Cohort C.
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Biological: T-cell Antigen Presenting Cells expressing truncated CD19 (T-APC)
Autologous CD4 and CD8 T cells transduced to express a truncated CD19 (CD19t) Transgene
Other Name: CD19+ Chimeric Antigen Receptor T-cells (CAR-T cells) |
Experimental: Cohort C
Participants will receive CD19-targeting CAR T cells. Participants for whom laboratory testing shows loss of CAR T cells within 6 months will be assigned to Cohort C. They will receive another CAR T cell infusion followed by up to 6 T-APC treatments.
|
Biological: T-cell Antigen Presenting Cells expressing truncated CD19 (T-APC)
Autologous CD4 and CD8 T cells transduced to express a truncated CD19 (CD19t) Transgene
Other Name: CD19+ Chimeric Antigen Receptor T-cells (CAR-T cells) |
Experimental: Cohort D
Participants will receive CD19-targeting CAR T cells. Participants who do not meet assignment rules for Cohorts A, B, or C will be followed after CAR T cell infusion in Cohort D.
|
Biological: T-cell Antigen Presenting Cells expressing truncated CD19 (T-APC)
Autologous CD4 and CD8 T cells transduced to express a truncated CD19 (CD19t) Transgene
Other Name: CD19+ Chimeric Antigen Receptor T-cells (CAR-T cells) |
- The adverse events associated with one or multiple CD19t T-APC product infusions will be assessed. [ Time Frame: up to 6 months ]Type, frequency, severity, and duration of adverse events will be summarized
- Determine the feasibility of deriving and administering a CD19t T-APC product [ Time Frame: 28 days ]Proportion of products successfully manufactured and infused
- Quantification of changes in the number of CAR T cells in peripheral blood before and after receiving CD19t T-APCs [ Time Frame: 6 months ]Multiparameter Flow Cytometry (MPF) from peripheral blood as a measure of magnitude and presence of CAR T cells before and after a dose of T-APCs
- Duration of B cell aplasia in CD19t T-APC treated patients [ Time Frame: up to 5 years ]MPF from peripheral blood as a measure of B cell aplasia

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Ages Eligible for Study: | 1 Year to 30 Years (Child, Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Inclusion Criteria:
- Diagnosis of recurrent or refractory CD19+ leukemia
- Adequate performance status
- Able to tolerate apheresis, including placement of temporary apheresis line if required
- Adequate renal, liver, cardiac, and respiratory function
- Adequate absolute lymphocyte count
- HIV negative; Hepatitis B and C negative within 3 months prior to enrollment.
Exclusion Criteria:
- Evidence of active clinically significant CNS dysfunction
- Evidence of active malignancy other than CD19+ malignancy
- Evidence of active GVHD, or on immunosuppressive GVHD therapy within 4 weeks prior to enrollment

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03186118
United States, Washington | |
Seattle Children's Hospital | |
Seattle, Washington, United States, 98105 |
Study Chair: | Colleen Annesley, MD | Seattle Children's Hospital |
Responsible Party: | Rebecca Gardner, Associate Medical Director, Immunotherapy Coordinating Center, Seattle Children's Hospital |
ClinicalTrials.gov Identifier: | NCT03186118 |
Other Study ID Numbers: |
PLAT-03 |
First Posted: | June 14, 2017 Key Record Dates |
Last Update Posted: | March 23, 2022 |
Last Verified: | March 2022 |
Studies a U.S. FDA-regulated Drug Product: | Yes |
Studies a U.S. FDA-regulated Device Product: | No |
pediatric young adult acute lymphoblastic leukemia CD 19 |
leukemia chimeric antigen receptor T cell |
Leukemia Neoplasms by Histologic Type Neoplasms |